Global shutters and high-speed flash photography
Feb 13, 2024
Global shutters and high-speed flash photography
Finally, the era of global shutters has arrived for full-frame professional cameras with the release of the Sony A9 III. I don’t use Sony cameras, but regardless, this is a huge innovation that will slowly take over the industry and push camera technology ahead.
I don’t expect global shutters to be in every new camera from now on. I expect that it will take five or more years for this technology to trickle down–and for Sony and other manufacturers to make a variety of global shutter cameras. Since Sony is the largest manufacturer of camera sensors, it will be the company dictating the pace at which global shutters are incorporated into cameras.
One of the downsides of global shutter sensors is that their dynamic range and noise characteristics are not as good as the older regular CMOS sensors. The Sony A9 III is more akin to an APS-C sensor of the same resolution when compared to similar 24 MP cameras.
Nonetheless, this is a small issue in light of the advantages–especially for sports and wildlife photographers. Also, with the new AI Denoise feature in Lightroom, noise doesn’t really matter anymore. ISO 12,800 on just about any camera is totally usable with a little AI Denoise applied in post-processing. Certainly, as new global shutter sensors are improved, the issues with noise and dynamic range will be addressed and improved upon.
History of high-speed flash synchronization
In my photography, as many of my readers will know, I have been pushing the envelope in terms of high shutter speed flash photography for quite some time now. I started out using the Elinchrom Ranger strobes with the PocketWizard Hypersync technology built into their radio transmitters, which allowed me to get up to around 1/1,600th second shutter speeds using strobes.
I first used Hypersync as an experiment photographing ice climbing way back in 2012 (as shown below). Hypersync was the first technique I found that allowed me to raise my shutter speed to freeze action and light up a subject that was more than 60 feet (18 meters) away from the strobe.
I then took those Hypersync techniques to Hawaii, where I used five 1,100 Ws Elinchrom Ranger strobes to light up a surfer on a wave that was around 500 feet (152 meters) away from the strobe, as shown below.
There is a behind-the-scenes video entitled Hypersync Surfing on my website from that experimental project. I wanted to see just how far I could push the flash technology–and I found out. While the Hypersync technology was clunky and hard to figure out, the results are hard to argue with.
The surfing image we created wasn’t the best surfing image ever, but it did offer insight into the possibilities–and it was, as far as I know, the farthest anyone had ever pushed strobe technology (outside of military applications).
At the same time that Hypersync was developed by PocketWizard, Profoto was hard at work implementing High-Speed Sync into their new B1 500 Ws flashes. High-Speed Sync (HSS) has been around for decades in Nikon and Canon speedlights as a way to sync flash at higher shutter speeds than the standard 1/250th second sync speed.
It was great to see this brought to more powerful strobes like the B1 and later the B1X, but it was still not anywhere nearly as powerful as the Hypersync technique noted above. The advantage of the HSS strobes was that they could sync at up to 1/8,000th second, whereas the Hypersync option depended greatly on the camera used and really only worked at up to 1/1,600th second on Nikon cameras.
To be clear, HSS and Hypersync function quite a bit differently. For a full explanation of HSS vs Hypersync (also later known as Hi-Sync), check out the blog post HS vs HSS that I wrote for Elinchrom.
With the release of the Elinchrom ELB400 way back in 2015, Elinchrom took the Hypersync technology and customized it to work much better for the ELB400 and, later, the ELB1200 strobes. In fact, on a flight home from Switzerland returning from a pre-production distributor meeting at Elinchrom HQ, I came up with fifty or sixty different names for the new technology, knowing that Elinchrom wanted to name it HS.
“Hi-Sync” is the name they chose off the list. Hence, the new Hi-Sync (HS) technology they created was the ultimate high-speed flash photography option on the market–until the release of the Sony A9 III. The HS technology they created allowed for syncing flashes up to 1/8,000th second shutter speeds with both the ELB 400 and the ELB1200 using the HS flash heads–which had a slow flash duration to help sync up the timing.
Essentially, the flash fired before the shutter, and this allowed the camera to use a slice of the light emitted by the flash. As shown below in an image created for the launch of the Elinchrom ELB1200, this gave us the ultimate in outdoor flash power.
The problem with HS technology was that it was hard to figure out. There was no auto setting, and you really have to experiment with it to make it work for you. In contrast, the Profoto B1 and later the B1X had TTL but modes just like a speedlight that allowed for full auto flash control. And hence, as you would suspect, many photographers went with the easier but much more limited option.
Using strobes with leaf shutters
After using the Hypersync and Hi-Sync technology for five or six years, I dove into the medium format world and purchased a Hasselblad H5D 50c, which used leaf shutters in the lenses instead of a focal plane shutter in the camera.
That camera system cost more than my car, so it was a huge investment. The leaf shutter in Hasselblad cameras allows for syncing strobes at all shutter speeds available on the camera. The H5D 50c only went up to 1/800th second, but their newer cameras had shutter speeds up to 1/2,000th second.
The leaf shutter was the original “global shutter” and essentially acted the same way. The full sensor (or piece of film back in the day) was fully exposed to the light with no restrictions at all shutter speeds, just like the newer global shutter in the Sony A9 III.
As shown below, I used the Hasselblad for both portraits and action images. The autofocus on the H5D was pretty pathetic, but with some workarounds, I could make it work for some sports, especially if I was using lighting.
I found the leaf shutter to be extremely powerful compared to other flash techniques, but in reality, I found using the HS (Hi-Sync) technology with my Nikon cameras and the Elinchrom ELB1200 was still more powerful for lighting up a subject from a far distance.
Sadly, Elinchrom has given up on the HS technology as none of their strobes has that built-in anymore. They have gone for the easier-to-use HSS option with TTL and auto modes, which totally makes sense as most people purchasing a flash want to create portraits, and the flash is relatively close in those scenarios.
The number of photographers using the Hi-Sync techniques to light up distant subjects was understandably a very small number, so it didn’t make much sense to keep producing strobes with that technology. The only manufacturer that still has HS technology (not HSS) incorporated into their strobes is Broncolor.
They have HS built into the Move 1200 L and the Siros 400 L and 800 L strobes. But with those options, Broncolor did not optimize the flash tubes to work specifically for HS, and hence, they only work in HS mode at the highest power settings where the flash duration is slow enough to make it work.
I still consider the Elinchrom ELB1200, which went out of production in 2020, to be the most technically advanced strobe ever created by any company. Sadly, they are very hard to find now. I will keep mine in good condition as long as I can until something better comes along.
The trick with using leaf shutters with your strobes was pretty simple. Your flash duration (i.e. how long the burst of light emitted from the flash) needed to be faster than your shutter speed for everything to work as expected. If the flash duration was shorter than the shutter speed, then you would end up clipping the flash, and the exposure would not match what your light meter read.
This is partly why Hasselblad shutter speeds only went up to 1/800th second and later to 1/2,000th second. Most strobes, even the high-end Profoto and Broncolor studio strobes, had relatively slow flash durations at the full power settings.
Even the incredible Bronocolor Scoro packs, which cost over $15,000 just for the pack itself, have a t0.1 flash duration of only 1/132 second. That is incredibly slow. They get much faster as you lower the power on the pack–as with all strobes.
The Profoto Pro-11, which costs an eye-bleeding $17,849 and that is just for the power pack, goes up to a wicked fast t0.1 flash duration of 1/17,500th second at the lowest power setting, but at full power, the t0.1 flash duration is a pedestrian 1/600th second.
[Note that the t0.1 flash duration notation is the most accurate available and commonly used notation for evaluating the actual flash duration. Most companies use the less accurate t0.5 notation as the numbers look more impressive.]
Using global shutters with strobes
Global shutters are sensors that read out all pixels at the same time. Older digital sensors scan the pixels on the sensor line by line. Some cameras, like the Nikon Z9 and the Sony A1, could do this incredibly fast, as shown below, but they were not reading all of the pixels at the same time. Hence, a global digital sensor is essentially the same as a leaf shutter used in medium-format cameras.
The only real-world difference is that they can achieve much higher shutter speeds than any leaf shutter ever could. For example, the Sony A9 III can go up to 1/80,000th second shutter speed.
As discussed in the previous section on using leaf shutters with strobes, the flash duration needs to ideally be shorter than the shutter speed when using a global shutter (or you will have to compensate the exposure slightly since you are only getting a slice of the light in the actual image).
This was the same scenario with leaf-shutter cameras from Hasselblad and Phase One. Another common issue when using leaf shutters is that the radio transmitter has to be more powerful and able to transmit the information to the flash faster than normal to trigger the strobe right when the shutter button is depressed.
Otherwise, you will end up clipping the light from the flash because of the delay in the radio trigger sending the signal to the flash/strobe. I had to switch my Elinchrom strobes over to a different “speed” mode to trigger the strobes faster with my Hasselblad.
With global shutters and fast shutter speeds, the reality is if we want to use flashes and/or larger, more powerful strobes with these new sensors, we need to invest in better strobes that have fast flash durations at all power settings.
What that means is the cheaper, slower HSS TTL strobes with very slow flash durations at the higher power settings are going to be tough to use with global shutters, especially outdoors where you want more power.
Even though they are quite expensive, the strobes shown above, like the Broncolor Move 1200L (left), Profoto Pro-11 (centre) and the Elinchrom FIVE (right) at lower power settings, are going to work much better than a lot of the cheaper strobe options like Godox and Westcott. I’m not saying you can’t work with those less expensive options, but just as with leaf shutters, the best results will always be gained with the higher-end strobes.
Both Broncolor and Elinchrom do have strobes that have much faster flash durations at the full power setting — somewhere in the order of 1/2,400th second (t0.5) at full power. Sports photographers have been using these types of fast flash duration strobes (from Elinchrom, Dynalite and others) for years because they needed fast flash durations at full power to freeze motion with the lights up in the rafters of stadiums (think Basketball and Hockey).
This is where a lot of the TTL HSS (like the Profoto B1X, Godox, etc.) strobes are going to have a lot of issues with the new global shutter cameras because their full-power flash durations are incredibly slow. Looking at the specs, the Broncolor Move 1200L would be one of the best strobes on the market for use with global shutters since it has a t0.1 flash duration of 1/2,300th second at 80% power–and it only gets faster the lower the power setting.
The Profoto D2 1,000 Ws moonlight is another excellent option. My old Elinchrom ELB1200 is in that same ballpark (as the Broncolor Move pack) when used with the Action flash heads–but sadly, it is no longer made.
As global shutter becomes the norm in future cameras, I foresee a slew of professional photographers ditching their cheaper strobes and upgrading to higher-end professional strobes like those made by Broncolor, Profoto and Elinchrom that have faster flash durations.
Profoto certainly has a phenomenal strobe in the Pro-11, but the weight and cost of that strobe are prohibitive. The Profoto D2, as noted above, is a great option for much less money–but it is still quite expensive. Broncolor has the venerable Siros L options with fast flash durations, but their strobes are the most expensive options across the board until you get up to the Profoto Pro-11 level.
If you still have an Elinchrom ELB1200 and the action flash heads, hold onto those, as they will be excellent strobes for the forthcoming global shutter future. Hopefully, the strobe manufacturers are aware of this change and will start developing new products with faster flash durations in anticipation of the forthcoming technology.
At some point, there will be no need for HSS or HS technology at all. The new global shutters will open up a new era of creativity in the photography world–and I, for one, am very excited to see what we can do with the new technology.
About Michael Clark
Michael Clark is an internationally published outdoor photographer specializing in adventure sports, travel, and landscape photography. He has risked his life and limbs on a variety of assignments to bring back stunning images of rock climbers, mountaineers, kayakers, big-wave surfers, and mountain bikers in remote locations around the world. If you would like to see more of his work, take a look at his website, Behance gallery, and Vimeo, follow him on Twitter and Instagram, and like his Facebook page. This article was also published here and shared with permission.
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